What is biochar?

Biochar is a charcoal-like material made from biomass waste via pyrolysis, where the material is heated in a low-oxygen environment. This waste may include leftover plant material from crops, manure, or food waste that would decompose and release greenhouse gases. Pyrolysis turns this biomass into a stable, carbon-rich material.

Biochar has a unique structure at the molecular level: a honeycomb-like carbon matrix that acts like a sponge. This structure gives biochar two unique abilities: improving soil properties and sequestering carbon. When mixed with soil, biochar can increase crops' water retention and nutrient availability. Its carbon has been trapped for thousands of years, preventing it from returning to the atmosphere as carbon dioxide. Carbon capture and storage mean biochar has potential as a climate solution.

What are the benefits of adding biochar to agricultural soil?

Some main ways biochar benefits agriculture are by improving soil fertility and crop productivity. Its porous structure allows biochar to retain nutrients and water, making it more accessible to plant roots. Biochar also increases the soil's ability to exchange positive ions, allowing it to trade and balance nutrients more effectively for optimal plant growth. This can reduce the need for chemical fertilizers in fields. The biochar also helps tilt, making clay-like soil more straightforward.

The benefits of biochar extend beyond the physical properties of the soil. It also changes soil biology by encouraging certain microbes. These microbes play a role in nutrient cycling, helping to convert nitrogen and phosphorus into plant-available forms. The stable carbon structure of biochar feeds these beneficial microbes for a long time. Diverse and balanced soil microbiology is essential for plant and soil health.

When mixed with agricultural soil, biochar sequesters carbon, which may decompose and release greenhouse gases. Studies show that biochar can sequester carbon for hundreds, if not thousands, of years. It is estimated that biochar has the potential to sequester 10% of annual global carbon emissions from the atmosphere if widely adopted. This is no small contribution to mitigating the effects of climate change.

Biochar production itself is compatible with circular economy principles as well. It takes waste biomass and recycles its carbon and nutrients back into the soil in a stable form. No waste goes to landfills, and a value-added product is created. Biochar systems can be decentralized on farms, saving energy and amending soil when needed rather than relying on external inputs.

Of course, like any new agricultural practice, biochar has challenges. For large-scale use, the cost and distribution of biochar systems need to be improved. Long-term effects on soil need to be monitored, as does the ability of biochar to transport pollutants if the feedstock contains them. The benefits of any soil amendment depend greatly on the soil type and climate zone.

However, research suggests that biochar has real potential as a tool for building more sustainable and climate-resilient agricultural systems. Biochar deserves serious consideration as we seek to revitalize degraded soils, reduce emissions, and adapt to climate change. If used wisely and paired with other regenerative practices, it can support productivity on working lands for generations while giving back to the planet. The future of biochar looks bright if we invest in improving its production and use.

In summary, this article has provided an overview of biochar—what it is, how it benefits soil and agriculture, its role in carbon sequestration, and the circular economy—as well as some of the challenges that need to be addressed. I aimed to discuss biochar and its ability to support more sustainable, climate-friendly agriculture in a detailed and accessible way. 

How to use How to use biochar?

Commercially sold items packaged or in bulk have undergone testing and analysis, and usage guidelines will be included. However, currently, there are only a few highly recommended applications for individuals handling it themselves. If you want to make your biochar, remember that research has shown that applying raw biochar alone in poor soil might hinder plant growth for up to six months.

• Rinse the raw biochar with water, then "charge" it by adding fertilizer or compost to about half of it. Spraying rates can range from 2 to 22 tons/acre, depending on the agricultural pattern and type of soil.

Consequently, one way to gradually increase the soil's content is to apply lower rates over two to three years.

Since 2012, the amount of research papers on biochar has increased by about five times, indicating that the issue is still quite popular. This wealth of research constantly expands our understanding of biochar and its potential to increase agricultural sustainability. However, there are still challenges to overcome, such as cost issues, the variety of biochar types and rates of application, and the compatibility of this technology with other soil health techniques, including mulching, cover crops, no-till, and composting. It's a dynamic field, and with ongoing research and development, we can expect to see improved recommendations in the coming years.